SANDY, Utah — In Major League Soccer, every match is important. But in 2013, every match between Real Salt Lake and the Portland Timbers has been really important.

Nothing less than first place in the Western Conference is on the line when the two teams meet Saturday in Portland. And, perhaps, a shot at the Supporters' Shield. Games like this are why, in the past couple of months, the two teams have become more than just Western Conference foes.

“To play the same opponent in really important matches is what starts rivalries,” RSL coach Jason Kreis told MLSsoccer.com recently. “That's why we're where we are with Seattle after playing them in the playoffs so many times in a row.”

Salt Lake and Portland have yet to face off in the playoffs; the Timbers have yet to make the postseason. But the three times the two teams have meet in 2013 have all been huge: On Aug. 7, Real Salt Lake eliminated Portland in the semifinals of the US Open Cup, 2-1.

As the two teams head into their fourth and final pre-playoffs meeting on Saturday at JELD-WEN Field, first-place Portland (53 points) have a one-point lead over second-place RSL (52) in the Western Conference standings. A win by either team will leave them in first headed into the last week of the regular season.

“This is what starts rivalries,” Kreis said. “Really stressful matches that mean something. Somebody taking the lead in the conference at that time or an Open Cup game.”

Adding to the importance of Saturday's match is the fact that neither team has clinched a playoff berth yet. Neither has any other team in the Western Conference, which is sort of “odd,” in Kreis' opinion.

“It's one thing to still have several teams still vying for the conference championship.” Kreis said. “But it's odd that nobody has clinched a playoff spot yet.

“When you're sitting there thinking, 'OK, we could win the Supporters' Shield, and we could miss the playoffs' — that's interesting.”